体积=1/3×3.14×（4÷2）²×10=41.87立方厘米
铅重=41.87×7.8=326.56克=0.32656千克体积41.87你是怎么算的呀？3.14×（4÷2）²×10=3.14×4×10=125.6 1/3×125.6≈41.87谢谢了+= =